Rick,
You could not use sinemet in the nasal route, you would get carbidopa into the brain as well as levodopa. The carbidopa would prevent the conversion to dopamine even of any small natural levodopa in the nrain. I imagine you would be totally imobile, incapable of making dopamine in the brain. Carbidopa can't pass the BBB so when taken orally in sinemet, the levodopa passes into the brain but not the carbidopa. I think you would need to use pure dopamine. You could use levodopa, but as I understand it, we have an impaired ability to convert it to dopamine.

Madelyn,
Yes glutathione is claimed to enhance dopamine formation,but I am not sure what you are suggesting. I am looking for ways to get pure dopamine into the brain. Enhancing natural production is a different topic, or have I misunderstood?
Ron